President Barack Obama is making waves with his first foray into triangulation — and so far, his strategy appears to be paying off.

After cutting a deal with Senate Republican leaders on an $858 billion tax package that drew protests from House Democrats, Obama scored another victory when more than 80 Senators voted Monday evening to proceed to a final vote on the plan.

And while the president’s strategy of edging out House Democrats in order to advance his agenda has triggered an assault from his left flank, senior Democratic aides are quietly accepting that his tack is a likely preview of how things will be in the 112th Congress.

“Obama is going to need significant Republican coordination and support to get anything done. Why would John Boehner [R-Ohio], the Speaker of the House, deal with the Minority Leader when they have more leverage with the White House?” a senior Senate Democratic aide asked.

“Some liberals will look at this as a betrayal. Some others will look at this as reality,” the aide said. “But I don’t think this is being done in a spiteful way by the administration.”

Obama has made passage of the tax package his No. 1 priority for the lame-duck session, and his two-pronged strategy for passing it has crystallized in recent days: Hurry the deal through the Senate and, in the meantime, wage a massive public campaign for its passage outside the Beltway to force House Democrats to vote “yes.”

White House Press Secretary Robert Gibbs has reinforced that game plan for the past week, pointing to the White House releasing dozens of statements of support for the deal from mayors, governors, lawmakers and even President Bill Clinton, who praised it last week following a White House meeting with Obama. Obama also sat down Monday with regional reporters from Ohio, Colorado, Iowa and Florida to tout the proposal.

“The notion that the view of some in Congress is monolithic to the viewpoint of every person in the party, I didn’t think that” even before recent polls showed Democratic support for passing the tax package, Gibbs said during a Monday briefing.

“I am not surprised by the polling that shows that a vast majority of people don’t want to see their taxes go up at the end of the year,” he said.

Under the package, the President George W. Bush-era tax cuts would be extended for two years for all Americans. The plan also extends unemployment insurance benefits for 13 months and cuts the payroll tax by 2 percent for one year.

One senior Democratic aide grumbled about the White House strategy of pitting House Democratic detractors against the general public.

“When has the mayor of Sheboygan ever moved a vote in the House, or the Senate for that matter?” the aide asked.

The pressure is already taking its toll on House Democratic leaders, who within a week have gone from saying they will oppose the package to saying its basic framework will pass.

“I think we’re going to have a vote on the Senate bill, and with possible changes,” House Majority Leader Steny Hoyer (D-Md.) said Monday during remarks at the National Press Club. “I believe that action is necessary and compromise was inevitable.”

Senior House Democratic aides said leadership has accepted that the Obama-GOP deal is essentially the package that must pass.

“Some Democratic leaders are unhappy with the White House, but they understand that things play out this way,” one top aide said.

Another senior Democratic aide said the main thing leadership is focused on is “making it clear to our Members we didn’t sign off” on the deal that Obama is pushing through without expressing distaste for it.

House Democrats could decide in a Caucus meeting tonight to stage a series of tax votes just to register their opposition to parts of the deal that benefit wealthier Americans. They could also decide to take a stand by amending the bill, sending it back to the Senate and forcing the chamber to strike its changes and send the bill back again for House consideration.

A senior House Democratic aide said today’s Caucus meeting will be “pivotal” in moving the issue forward. The message from leadership will be “come together now so we can go home,” the aide said.

Senate Democratic aides predicted a relatively smooth voting process in their chamber, despite the fact that some Democrats won’t vote for the bill if it includes perks for the wealthy.

“We don’t like all of it, but there’s more good than bad and we just have to swallow this and get it done,” the aide said.

It remains to be seen how Obama could lean on triangulation for his other priorities for the lame-duck Congress, which include passage of the Strategic Arms Reduction Treaty, a continuing resolution or an omnibus spending bill to keep the government funded, and votes on contentious measures important to his base: the DREAM Act to provide a path to citizenship for some illegal immigrants and a repeal of the military’s “don’t ask, don’t tell” policy banning openly gay service members.

A senior Democratic aide said that in order for Obama to find success through dividing his party, he will need a viable political strategy that boosts his approval ratings for 2012 and will need to be adept enough in negotiations to see a deal through to the end.

“Clinton was just devious about this stuff. He got it. He understood how to play politicians against each other,” the aide said. “We’ll see if Obama’s got it in him.”